Free NCLEX-RN Pharmacology Practice Questions
Free NCLEX-RN pharmacology and parenteral therapies practice questions with full rationales — medication safety, adverse effects, and nursing implications.
A client is about to start timolol ophthalmic drops for open-angle glaucoma. Which item in the health history should the nurse discuss with the prescriber before the first dose?
Correct answer: C
Timolol is a beta-blocker, and enough of it is absorbed from the eye into the bloodstream to trigger bronchospasm and slow the heart. Active asthma with wheezing is the finding that could turn dangerous, so it is raised with the prescriber before the drug is started. The eye-related items look more relevant to an eye drug but do not carry the systemic beta-blocker risk.
Why the other options are wrong
- A. Seasonal allergic conjunctivitis affects external ocular mucosa and does not interact with systemic beta-adrenergic receptor blockade. Key distinction: Localized ocular allergies may require antihistamine drops but do not contraindicate timolol.
- B. Contact lens wearers must remove soft lenses before instilling timolol and wait 15 minutes before reinsertion to avoid benzalkonium chloride absorption. Key distinction: Lens wear requires proper administration timing, not drug discontinuation or provider consultation.
- D. A family history of cataracts reflects lens opacification and has no physiological overlap with beta-receptor activity or aqueous humor dynamics. Key distinction: Cataracts affect lens clarity, whereas timolol targets ciliary body aqueous production.
Key takeaway: Ophthalmic timolol is absorbed systemically and can cause bronchospasm and bradycardia; screen for asthma, COPD, and heart block.
A client taking phenelzine, a monoamine oxidase inhibitor (MAOI), develops a sudden severe throbbing headache, palpitations, and a blood pressure of 210/120 after eating at a restaurant. Which is the nurse's priority action?
Correct answer: C
MAOIs block the breakdown of tyramine, so eating tyramine-rich foods (aged cheese, cured or smoked meats, fermented foods, draft beer) can trigger a hypertensive crisis. A sudden severe headache, palpitations, and a blood pressure of 210/120 are that crisis, so the nurse holds the MAOI and prepares a rapid-acting antihypertensive while getting help. Giving another dose adds to the offending drug, lying flat with the legs elevated raises the blood pressure and cerebral pressure and is a position for shock, and a benzodiazepine treats anxiety and does not lower a dangerously high blood pressure.
Why the other options are wrong
- A. Administering another MAOI dose exacerbates enzyme blockade and amplifies lethal sympathetic overdrive. Key distinction: Offending medications must be stopped immediately during acute toxic reactions.
- B. Elevating the legs increases venous return and intracranial pressure, worsening cerebral hypertension during a hypertensive crisis. Key distinction: Elevate the head of the bed for hypertensive emergency, but elevate legs for circulatory shock.
- D. Benzodiazepines treat central anxiety but do not block peripheral alpha-1 vasoconstriction driven by excessive norepinephrine. Key distinction: Hypertensive emergencies require direct vascular smooth muscle relaxation or alpha-adrenergic blockade.
Key takeaway: On an MAOI, tyramine-rich foods can cause a hypertensive crisis. Hold the drug and prepare a rapid-acting antihypertensive; do not continue the drug, lay the client flat, or treat it as anxiety.
Which instruction is most important for a client with diabetes who is starting a beta-blocker?
Correct answer: B
Beta-blockers can mask the usual warning signs of hypoglycemia, such as a fast heart rate and tremor, so a client with diabetes must monitor glucose closely, and the drug should never be stopped abruptly because rebound hypertension or chest pain can occur. Stopping when the rate feels slow, skipping glucose checks, and doubling a missed dose are all unsafe.
Why the other options are wrong
- A. Checking the pulse is important, but it does not address the immediate life-threatening risk of masked hypoglycemia in a client with diabetes.
- C. Clients with diabetes must monitor blood glucose more frequently, not less, because physical warning signs are masked.
- D. Taking extra doses of a beta-blocker can cause severe bradycardia, hypotension, and block cardiac conduction.
Key takeaway: Beta-blockers mask hypoglycemia signs and must not be stopped abruptly.
A client received cyclopentolate (a cycloplegic and mydriatic) drops in the clinic before an eye examination. Which instruction is most important at discharge?
Correct answer: C
Mydriatic and cycloplegic drops widen the pupil and relax focusing, so the client has blurred vision and painful glare until the effect fades over several hours. The most important instruction protects safety: wear sunglasses for the glare and do not drive until vision clears. Flushing with tears does not speed the wear-off, near vision is blurred rather than sharper, and resting in a dark room may feel comforting but does not address the driving-safety risk.
Why the other options are wrong
- A. Cyclopentolate binds to ocular muscarinic receptors, and instilling artificial tears will not dislodge the bound drug or accelerate metabolic clearance. Key distinction: Flushing with tears only dilutes local lubrication without hastening recovery from pharmacologic blockade.
- B. Cycloplegia paralyzes ciliary muscle contraction, disabling the lens mechanism required to focus on near objects and rendering near vision blurry rather than sharp. Key distinction: Distance vision remains relatively preserved while near vision accommodation is temporarily lost.
- D. Resting in a dark room alleviates light discomfort but fails to address active environmental hazards if the client attempts to drive home from the clinic. Key distinction: Comfort measures (darkened room) do not replace critical safety mandates (prohibiting driving).
Key takeaway: Mydriatics and cycloplegics cause pupil dilation, blurred vision, and photophobia; advise sunglasses and no driving until it clears.
A client who has been taking metoclopramide reports involuntary lip smacking and repetitive tongue movements. Which action should the nurse take?
Correct answer: C
Involuntary movements of the lips and tongue on metoclopramide may be tardive dyskinesia, which can become permanent. The definitive action is to stop the offending drug and notify the provider. Any option that keeps the client on the drug, even at a lower dose or with a medication to mask symptoms, allows the movement disorder to progress.
Why the other options are wrong
- A. Diphenhydramine may ease acute extrapyramidal symptoms, but the offending drug must be stopped; continuing it lets tardive dyskinesia advance.
- B. Lowering the dose while continuing exposure still allows the movement disorder to progress; the drug is withheld.
- D. These movements are a warning sign of tardive dyskinesia, not an expected effect, so the drug is not given.
Key takeaway: Facial or tongue movements on metoclopramide suggest tardive dyskinesia; hold the drug and notify the provider.
The nurse reviews a client's use of several gastrointestinal medications. Which client statements indicate correct understanding? Select all that apply.
Correct answers: o1, o2, o3, o4
Reporting tongue and lip movements on metoclopramide (possible tardive dyskinesia), knowing a magnesium antacid can cause loose stools, taking psyllium with a full glass of water, and spacing an antacid from other pills are all correct. Chewing an omeprazole capsule destroys its acid-protective coating, and sucralfate needs an empty stomach before meals, not right after eating.
Why the other options are wrong
- o5. Chewing an omeprazole capsule destroys the enteric coating, allowing stomach acid to inactivate the drug before it reaches the small intestine where it is absorbed. The capsule must be swallowed whole.
- o6. Sucralfate requires an empty stomach and an acidic environment to form a protective barrier over the ulcer bed. Taking it after meals binds it to food particles, making it ineffective. Key distinction: Mucosal protectants are timed before meals to coat the ulcer, whereas antacids or pancreatic enzymes may be timed around meals for different therapeutic reasons.
Key takeaway: Report metoclopramide tongue movements; magnesium antacids loosen stool; psyllium with water; space antacids; swallow PPIs whole; sucralfate before meals.
A client is receiving IV magnesium sulfate. Which findings would indicate magnesium toxicity? Select all that apply.
Correct answers: o1, o2, o3, o5
Magnesium toxicity depresses the nervous system: the respiratory rate falls below 12, deep tendon reflexes disappear, urine output drops (which lets magnesium build up), and the client becomes drowsy with a decreasing level of consciousness. Brisk reflexes with anxiety and a rising blood pressure with tachycardia are not the toxicity pattern.
Why the other options are wrong
- o4. Brisk reflexes (3+) and anxiety are signs of neuromuscular irritability and worsening preeclampsia, not magnesium toxicity. Magnesium sulfate is a central nervous system depressant that decreases neuromuscular excitability, which causes reflexes to diminish or disappear. Key distinction: Worsening preeclampsia causes hyperreflexia (e.g., 3+ or 4+), while magnesium toxicity causes hyporeflexia or absent reflexes.
- o6. A rising blood pressure and tachycardia indicate worsening gestational hypertension or preeclampsia, not magnesium toxicity. Magnesium sulfate has a mild vasodilatory effect that typically lowers or stabilizes blood pressure rather than raising it. Key distinction: Magnesium toxicity leads to hypotension and bradycardia due to severe central nervous system depression.
Key takeaway: Magnesium toxicity: respiratory rate under 12, absent reflexes, low urine output, and decreasing level of consciousness.
A client taking prednisone as an immunosuppressant tells the nurse, "I felt better, so I stopped taking the pills a few days ago." Which response by the nurse is best?
Correct answer: D
Long-term corticosteroids suppress the body's own cortisol production, so an abrupt stop can trigger acute adrenal insufficiency. The dose must be tapered down gradually under the provider's direction, never stopped on the client's own. The other responses endorse stopping or self-adjusting the drug, which is unsafe.
Why the other options are wrong
- A. Prednisone has a short half-life, and its physiological effects fade within 12 to 36 hours; it does not remain active to protect the client. Key distinction: The body's cortisol production cannot resume immediately after stopping the drug.
- B. Adrenal crisis can cause life-threatening circulatory collapse before symptoms like swelling return; restarting the drug only after symptoms appear is unsafe. Key distinction: Fluid retention is a sign of steroid excess, whereas lack of steroids leads to shock.
- C. A steroid taper requires step-wise dose reductions; simply taking the remaining full-dose pills until the bottle is empty does not allow adrenal recovery. Key distinction: The dose must be gradually decreased on a planned schedule.
Key takeaway: Never stop long-term corticosteroids abruptly; taper the dose to avoid adrenal insufficiency.
The nurse teaches a client how to use an epinephrine auto-injector for anaphylaxis. Which statements indicate correct understanding? Select all that apply.
Correct answers: o1, o2, o3, o4
The epinephrine auto-injector is injected into the muscle of the outer thigh and held in place for several seconds so the full dose is delivered. Because effects can wear off and the reaction can return, the client calls 911 after using it and carries a second injector. The injector is stored at room temperature rather than in a hot or cold car, and the client still seeks emergency care even if symptoms improve, because a biphasic reaction can recur hours later.
Why the other options are wrong
- o5. Epinephrine degrades when exposed to extreme temperatures; storing the auto-injector in a vehicle glove box can make the medication ineffective. Key distinction: The device must be stored at room temperature and kept out of hot or cold cars.
- o6. Epinephrine is short-acting, and symptoms of anaphylaxis can return hours later in a biphasic reaction; emergency medical evaluation is always required. Key distinction: Symptom improvement does not guarantee the reaction has ended.
Key takeaway: Epinephrine auto-injector: inject into the outer thigh, hold several seconds, call 911, and carry a spare; use early.
An Rh-negative client who is 28 weeks pregnant asks the nurse why she is being offered the Rho(D) immune globulin (RhoGAM) injection. Which explanation is correct?
Correct answer: A
An Rh-negative mother can be exposed to Rh-positive fetal blood and form antibodies that attack the red cells of a future Rh-positive fetus. Rho(D) immune globulin works by preventing the mother's immune system from forming those antibodies. It does not supply the missing Rh factor, change the mother's blood type, or remove fetal cells from her circulation. It is given around 28 weeks and again within 72 hours of birth of an Rh-positive newborn.
Why the other options are wrong
- B. Rho(D) immune globulin does not supply the Rh antigen or change the mother's Rh status. It is a preparation of passive antibodies that targets and clears Rh-positive cells from the mother's bloodstream.
- C. Fetal cells can enter maternal circulation during normal pregnancy or trauma. Rho(D) immune globulin destroys these fetal cells after they enter the mother's circulation, not while they are still inside the fetus.
- D. Rho(D) immune globulin is an immunizing agent, not a hematinic. It has no effect on maternal iron stores or red blood cell count.
Key takeaway: Rho(D) immune globulin prevents an Rh-negative mother from forming antibodies against Rh-positive fetal blood.